Comment by jasode | Hacker News Reader

Comment by jasode | Hacker News Reader

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>My personal belief? We just don't teach it.[...] Grads come out with a 4 year headstart on a non-FP paradigm,

I don't agree the lack of proactive education is the reason FP isn't the norm. Your conclusion doesn't take into account the counterfactuals:

- C Language took off in popularity despite BASIC/Pascal being the language more often taught in schools

- languages like PHP/Javascript/Python/Java all became popular even though prestigious schools like MIT were teaching Scheme/Lisp (before switching to Python in 2009).

You don't need school curricula to evangelize programming paradigms because history shows they weren't necessarily the trendsetters anyway.

On a related note, consider that programmers are using Git DVCS even though universities don't have formal classes on Git or distributed-version-control. How would Git's usage spread with everybody adopting it be possible if universities aren't teaching it? Indeed, new college grads often lament that schools didn't teach them real-world coding practices such as git commands.

Why does Functional Programming in particular need to be taught in schools for it to become a norm but all the other various programming topics do not?

> Why does functional programming need to be taught in schools but all the other various programming topics did not?

Because I think it is harder for people who have programmed with other paradigms - following an inverse law, most things should get easier to learn with experience, not harder. It's foreign, it's weird, it's back to front. It doesn't have an immediately obvious benefit to what people are used to, and the benefits it has come at scale and up against the wall of complexity (in my opinion). It's hard to adopt upfront. At the small scale it's often painful to use. The syntax is weird. It's aggressively polymorphic, reasoning in abstractions rather than concretions. I could go on (and yet I still adore it).

The only reason FP has been successful as it is, is because its evangelists are incredibly vocal, to the point of being fucking annoying sometimes. It's had to be forced down people's throats at times, and frankly, there's no better place to force a paradigm down someone's throats than at a university, where non-compliance comes at academic penalty, and when the mind is most impressionable.

>Because I think it is harder for people who have programmed with other paradigms

I still think there's something missing in your theory of cause-&-effect. A math topic like quaternions is hard and yet programmers in domains like 3d graphics and games have embraced it more than FP.

I also think Deep Learning / Machine Learning / Artificial Intelligence is even more difficult than Functional Programming and it seems like Deep Learning (e.g. Tensorflow, Pytorch, etc) will spread throughout the computer industry much more than FP. Just because the topic is hard can't be the defining reason.

>The only reason FP has been successful as it is, is because its evangelists are incredibly vocal,

But why is FP in particular only successful because of loud evangelists? Why can't FP's benefits be obvious so that it doesn't require evangelists? Hypothetical example:

- Company X's software using FP techniques is 10x smaller code base, 10x less bugs, and 10x faster feature development -- than Company Y. Ergo, this is why Company X is worth $10 billion while Company Y is only worth $1 billion or bankrupt.

If you think the above would be an unrealistic and therefore unfair comparison, keep in mind the above productivity improvement happened with the industry transition from assembly language to C Language. (A well-known example being 1980s WordPerfect being written in pure assembly language while MS Word was written in C Language. MS Word was iterating faster. WordPerfect eventually saw how assembly was holding them back and finally migrated to C but it was too late.) Yes, there's still some assembly language programming but it's niche and overshadowed in use by higher-level languages like C/C++.

If Functional Programming isn't demonstrating a similar real world massive productivity improvement to Imperative Programming, why is that? I don't think it's college classes. (Again, see all the non-PhD enthusiasts jumping on the free FastAI classes and brushing up on Linear Algebra to teach themselves deep learning.)

> Why can't FP's benefits be obvious so that it doesn't require evangelists?

Because there aren't immediate benefits. They only pop out at scale and with complexity, as I said.

> similar real world massive productivity improvement to Imperative Programming

Because there isn't. It's a reasonable benefit, but it's not transformative. I think it's there, enough to commit to FP completely, but the massive productivity improvement doesn't exist, or at least, only exists in specific cases, e.g. the WhatsApp + Erlang + 50 engineers parable (you could argue that this is due to the actor model and BEAM, rather than FP. An argument for a different day).

I feel like this hard + reasonable benefit isn't really efficient utilisation of people's time, especially when there's things like Deep Learning floating around. I think the immediate reaction to a lot of what FP evangelists claim is a shrug and a "I guess, but why bother?"

>> Because there aren't immediate benefits. They only pop out at scale and with complexity, as I said.

What about low-barrier situation with scale and complexity ?

An imaginary situation:let's say you start building your system from a large open-source project that needs a lot of customization.

Will FP be of big enough benefit than ?

I'm curios about the answer, but for a sec, let's assume it does:

Than could it be a uni project ? dig into the belly of 2 beast projects, one FP, one OOP. And see the difference in what you could achieve.

Could something like that work ?

Exactly. As just an anecdote, my intro do FP class in university was taught by a professor who tended to rant about different levels of purity and elegance between his favorite and least favorite languages. Of course, the favorite was his pet project and we had to spend most of the class using it. I also know that Emacs is partly written in Lisp because it was the only editor he would touch.

FP can't even sell itself well in school as a language where useful things can be done, when the student is stuck in a deep valley of ___morphisms and other alien concepts with claims of aesthetic elegance as the only motivation. I recall the math nerds loved it as relief over C that the rest of the department used, but with me being rather mediocre in math, the weirdness and cult-like vibe from the prof and TA left a really bad taste. The impression was so deep that I have no issues recalling this class a decade later. I've never touched any FP since, unless you count borrowing clever lambda snippets.

The sad part is that this is a common experience - universities have done a bad job at teaching FP. I think there are good pieces of FP education, particularly Learn You a Haskell and https://github.com/data61/fp-course - friends have gone through these have questioned "why wasn't I taught like this the first time around".

> I've never touched any FP since, unless you count borrowing clever lambda snippets.

I'd urge you to give it another shot if you have spare time. Even in spite of all the dogshit things associated with it, it's a paradigm I've bet my career on.

Noted--thank you!

>It's had to be forced down people's throats at times, and frankly, there's no better place to force a paradigm down someone's throats than at a university, where non-compliance comes at academic penalty, and when the mind is most impressionable.

That's also a great way to make people hate it. An example is literature classes with mandatory reading and how they make students hate reading fiction.

I would also say that this might turn off more students from programming. We had functional programming in uni, where we learned Haskell. Maybe a handful of students liked it or were neutral about it, the vast majority seemed to have a negative view of it.

I think that FP is just more difficult to learn. Just look at essentially any entry level programming course and how people understand loops vs recursion.

Okay, so FP is more difficult to learn. Assume for the sake of this argument that FP has a tangible benefit over other paradigms, that manifest themselves at scale. You're tasked with educating students in this paradigm, but they complain that it is more difficult than the techniques that they are used to.

What do you do?

I don't know, because I'm not qualified for it. I had to pass a course on FP, but frankly, I wouldn't be able to do anything with it in practice, let alone teach it. My only personal experiences with it were negative. If it had been Haskell that was the entry level programming course, then I probably would never have learned to program.

Okay, so given this answer here's what I would do:

1) I wouldn't make it the entry level course. It's clearly a paradigm that's used by a minority of people, so it doesn't make sense to start educating students with it.

2) I mandate that all students take it, maybe in their 3rd year. We're going to mandate it because there are tangible benefits (which we've assumed for the sake of this argument). They're going to find it harder and more confusing because its's different to what they're used to. A lot of them may not like it and won't see immediate benefits. Some may even come to dislike it. Frankly, I don't care, some will pick it up and learn about it further. And when the students that disliked it inevitably run it into the future, they sufficiently prepared to deal with it.

We're back to square 1: forcing it down student's throats. If you still think that we shouldn't be forcing students to learn FP in schools, I think you have a problem not with FP but with structured curriculums.

I validate your assumption against reality.

If FP is not mandatory at Google-scale, it isn’t mandatory at your scale.

The kind of problems that emerge at scale are not the kind of problems FP tackles.

Sorry, I mean scale as in "large scale projects".

Spark is the quintessential Google-scale FP project - it was even born out of the MapReduce paper by Google!

And there's plenty of other large-scale projects that are arguably in an FP style specifically to deal with the problems associated with scaling them: the Agda/Isabelle proof checkers, the seL4 kernel, the Chisel/FIIRTL project, Erlang/OTP, the Facebook Anti-Spam system (built on Haxl), Jane Street's massive investment into OCaml, Twitter's investment into Scala.

Not all scale problems are distributed problems. Some distributed problems are tackled by FP, and some aren't. Ultimately, these large-scale projects pop up at similar rates to the usage of the language themselves. It's intellectually dishonest to say that FP can't be used to tackle large scale problems, and the problems that occur at scale, because its repeatedly validated that it can.

It is also intellectually dishonest to strawman an argument.

I didn’t say it is impossible to do X with FP - I said it is not necessary to do X in FP. You can convince yourself of that by looking for larger-scale non-FP counter-examples to the ones you've cherry-picked.

Every single large scale problem is a distributed problem simply because human societies are multi-agent distributed systems and programming languages are human-computer interfaces.

The issues at scale are systemic and arise from the design trade-offs made when your system's requirements bumps against the limits of computation. No language/paradigm can work around those.

The best a language can do is abstract-away the complexities behind a problem - solve it once (in the language/paradigm's preferred way) and give the human an interface/concept to work with.

Okay, I got really confused by this whole mandatory thing. I never said FP should be mandatory at scale. I said it had a moderate benefit at scale. You respond with "well actually, it's not mandatory at Google-scale" so I assumed that you were trying to refute the fact that FP has benefit at scale.

You also followed this up with

> The kind of problems that emerge at scale are not the kind of problems FP tackles.

I cherry picked these examples to demonstrate that you're completely talking out of your ass here.

> I didn’t say it is impossible to do X with FP - I said it is not necessary to do X in FP. You can convince yourself of that by looking for larger-scale non-FP counter-examples to the ones you've cherry-picked.

I never said it wasn't possible to tackle these problems without FP.

You need to get rid or the assumption that "if X is better than Y at task Z, everyone will use X rather than Y for task Z". You've used that line of logic to attempt to invalidate FP's capabilities. It simply does not make sense.

You give them difficult real-world problems where FP is helpful.

But university computer science seems to be specialized from mathematics instead of generalized from engineering, so CS professors most of the time have no idea about real world problems. At least here in Germany, where the problem seems especially bad.

> C Language took off in popularity despite BASIC/Pascal being the language more often taught in schools

While C is less constrained, it's structurally very similar to Pascal; they don't differ in paradigm and are in the same syntax family.

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